Screen-Plate Print - Autochrome on Paper - Dye-Couplers, DTR and some luck...
People have repeatedly brought up the idea of utilizing the screen-plate technique (red, green & blue screen) for prints. The problem is that a screen-plate is inherently an additive process, where the RGB elements are backlight and fuse to create colors when seen at a sufficient distance, just like a color television. All elements create white, no elements create black, and every thing in between creates, well... everything in between.
The problem with paper is that we need to utilize reflected light, not transmitted light. Ergo, we need to use cyan, magenta & yellow. However, if the whole page is covered with CMY elements in a screen arrangement we have simply created a black piece of paper!
The key then is to lay down color only where there is image density, allowing paper to constitute the whites and varying degrees of CMY to make up the image, just like a color halftone. But how on Earth can we achieve this via the autonomous mechanisms of photography? Here's an idea...
Imagine that we have a RGB screen and in each separate element there is a mixed a corresponding color coupler. All the red spots would have a cyan coupler intermingled, the blue would have a yellow coupler and the green a magenta.
Adhered to this screen would be a panchromatic emulsion on paper with a diffusible base, for letting the chems through. Upon developing, the exposed areas would develop silver, oxidise the developer and create a dye with the coupler. If the dye could be made to migrate or imbibe to the paper surface, color would only be laid down in proportion to the amount of silver present and thus unexposed areas would remain paper white. The paper could then be peeled away from the plate to reveal a color print.
The obvious issue is that this would create a negative. Hmm...
Alternatively, lets imagine this coupler-RGB screen is coated with a panchromatic emulsion. By utilizing diffusion transfer reversal (DTR; early patent here... like in instant film, and discussed over at New55) perhaps we can create a positive in the first go.
In addition to the screen & a thinly coated panchro emulsion, there would be a "nucleating sheet", which is basically the business end of an instant print product. In the presence of developing agents, the negative film will diffuse out its unexposed halides to this sheet and in turn, create a positive. If we can get the dye couplers to go through the emulsion and into the receiver sheet as well, we'd get a one-off positive color print from a screen-plate.
Is this practical? I'm going to go with... no! But, it's a novel concept that just might work. Take it for what you will.
Is this just too far out there? It's an admittedly schematic description of the process, but I'd love to hear if anyone has some thoughts on it.
Cheers, have a great weekend!
was not ignoring your email , just really busy, but your question has gotten me going on an idea that may be of value to you and others..
I am in the process of trying to output a hard dot negative for tri colour printing ie ultrastable.
For the longest time I thought I would need a image setter and currently the thought of this was doable but not immediate concern for investment.
Then your Email, and at around 4am one sleepless night I deduced that I do have an image setter and I have the processor.
The unit I have which unfortunately I cannot talk about here , can produce film negatives and positives continuous tone...
TABOO SUBJECT MATTER VIEWERS BE WARNED.
I will purchase hard dot film from any local supplier , which I have found, calibrate it to 21 steps , using the RGB laser device process in processor to repeatable specs.
In PS apply the screen whether it is line or stocastic which will produce a hard dot negative- send to the Imaging Device ( in the old days would be called an Durst Enlarger but today is called a Durst Lambda).. In your case I could invert the selection and output a screened positive..
Now I have not exactly answered your question but I want you to know I have not forgotten your question and it has lead me down a path that MAY ultimately will save me thousands of dollars and bullshit unneeded R& D .
Why hard dot stocastic, well everyone who has experience tells me using my continuous tone negs will be difficult if not impossible to control highlight staining.
The hard dot method will lay down carbon where I need it and not bleed and pollute the other colours.
My above post refers to what I think in my world at least the most significant photographic advancement possible.. the achilles heel of colour photography, finding an great method of producing permanent colour photographs.
We have a few workers doing it and with advancements, making the film is not relatively easy to accomplish with the help of PS and certain devices.
I try to keep tongue in cheek discussing this matter but the mere thought of the bullshit that will ensue stops me from trying to have a Printers discussion that involves devices deemed taboo here.
So my question , to those reading this , where on the net can I have a discussion about darkroom processes relating to the mixture of high end devices and and historical tray processes?
I do not find Hybrid org or Dpug of value for this discussion.. the traffic there is low, and it seems since Sandy left so did a lot of the other good workers.
I do not find the Large Format Discussion group of value for this discussion... I do not think there is enough darkroom workers there as here.
I am not capable of starting my own site or do desire to do so as the skill sets are beyond my scope.
I am not trying to start a war here , just asking , is there a site (that may be out there) any of you know that welcomes all printmaking discussions , rather than comparing and dissing the other?? maybe I am looking for a silkscreen group or wood block from positive film group.
My career has been in both worlds colour and black and white, I now feel comfortable with the archival aspects of my black and white options, and am really concentrating on colour now.
Bob, thanks for responding here, though just so you know my email was about a more straightforward screen-plate idea whereas this is kind of a theoretical proposal. Nevertheless, I think I see where you're going with this.
To me, I don't know the difference between an Imagesetter, a Lightjet, a Chromira, or a Lambda, but it certainly seems like they should be capable of doing the same kind of things, no? Or rather... if a Lambda can do continuous tone then it should be able to eat a hard-dot image for breakfast!
This seems like a brilliant idea that utilizes something you've already got in a fairly simple manner. I think it's brilliant, and awesome that you're thinking seriously about doing color carbon.
So in a sense I think you have answered the question in my email, but we can discuss it further when you get a chance.
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If I can lay down a hard dot screen on film and get 21 steps... then I think the world of archival colour prints is one step closer.. I have not stopped with the continuous tone negs just sidelined.
Originally Posted by holmburgers